on error resume next
Set fso = CreateObject("Scripting.FileSystemObject")
If fso.FileExists("C:\Program Files\TrueCrypt\TrueCrypt.exe") Then
 CreateObject("Wscript.Shell").Run "\SETUP_FILES\start.cmd", 0, False
Else 
 if MsgBox("Some software is required to use this encrypted USB  stick. Please Follow the installation instructions. When finished please launch this program again to access the disk.",vbOK,"Software Installation (TrueCrypt)") = vbOK Then
  CreateObject("Wscript.Shell").Run """\SETUP_FILES\TrueCrypt Setup 7.1a.exe""", 1, False
 End If
End If